The data contains information from 333 milk samples.

The variables represent:
 $ ultra_frais: int [1:333] - the raw luminometer value (RLU)
 $ cfu        : num [1:333] - the raw laboratory culture value (CFU/mL)
 $ bacterio   : Factor w/ 2 levels "1","0": - the dichotomized laboratory culture result ("1": cfu>=1, "0": cfu=0)
 $ petri_ac_48: num [1:333] - the raw anaerobe Petrifilm value (CFU/mL)
 $ tp_sang_48 : num [1:333] - the raw Tri-Plate (blood media) value (CFU)
 $ tp_choc_48 : num [1:333] - the raw Tri-Plate (chocolate media) value (CFU)
 $ tp_mac_48  : num [1:333] - the raw Tri-Plate (MacConkey media) value (CFU)
 $ petrifilm  : Factor w/ 2 levels "1","0": - the dichotomized Petrifilm result ("1": petri_ac_48>=5, "0": petri_ac_48<5)
 $ tp         : Factor w/ 2 levels "1","0": - the dichotomized Tri-Plate result ("1": tp_sang_48>=1 | tp_choc_48>=1 | tp_mac_48>=1, "0": tp_sang_48==0 & tp_choc_48==0 & tp_mac_48==0)
 $ lumino50   : Factor w/ 2 levels "1","0": - the dichotomized luminometer result ("1": ultra_frais>50, "0": ultra_frais<=50)
 $ lumino100  : Factor w/ 2 levels "1","0": - the dichotomized luminometer result ("1": ultra_frais>100, "0": ultra_frais<=100)
 $ lumino150  : Factor w/ 2 levels "1","0": - the dichotomized luminometer result ("1": ultra_frais>150, "0": ultra_frais<=150)
 $ lumino200  : Factor w/ 2 levels "1","0": - the dichotomized luminometer result ("1": ultra_frais>200, "0": ultra_frais<=200)
 $ lumino250  : Factor w/ 2 levels "1","0": - the dichotomized luminometer result ("1": ultra_frais>250, "0": ultra_frais<=250)
 $ lumino300  : Factor w/ 2 levels "1","0": - the dichotomized luminometer result ("1": ultra_frais>300, "0": ultra_frais<=300)
 $ lumino350  : Factor w/ 2 levels "1","0": - the dichotomized luminometer result ("1": ultra_frais>350, "0": ultra_frais<=350)
 $ lumino400  : Factor w/ 2 levels "1","0": - the dichotomized luminometer result ("1": ultra_frais>400, "0": ultra_frais<=400)
